The reply was “actually, it is.” Two years later I’d add that it still is, but to a much smaller degree. The key to this is the realization that: (1) 100 percent viewability is incredibly difficult; and, (2) estimations about viewability are accurate enough. As a result, marketers are paying only for ads that are viewed. This is not an exact process, but it’s enough to put the viewability issue to rest.